A 2D Array of Copper(I) Catenane Catalyst Grafted on a Metal-Organic Layer for High Fidelity Cross-Coupling

While Earth abundant metals are green and sustainable alternatives to precious metals for catalytic chemical conversions, the fast ligand exchange involving most of these metals renders their development into robust, reusable catalysts very challenging. Described in this work is a new type of heterogeneous catalyst derived from a 2D metal-organic layer (MOL) grafted with catenane-coordinated Cu(I) complexes. In addition to the good substrate accessibility, easy functionalization and other favorable features due to the MOL support, the anchored catenane ligands also provide a well-defined coordination environment and good kinetic stability to the coordinated Cu(I). Catalytic studies using phenols and bromodicarbonyls as the substrates showed that the Cu(I) catenane-grafted MOL resulted in the exclusive C–O coupling of the substrates, whereas a control catalyst in which the catenanes are replaced by non-interlocked macrocyclic ligands was found to lead to also a C–C coupling due to the uncontrolled formation of oxidized copper active site. The integration of mechanically interlocked catalyst to extended framework support thus represent an unexplored potential of exploiting labile, Earth-abundant metals for sustainable catalysis under challenging conditions.